DE102014117770A1 - Apparatus and method for supplying fuel using an EGR cooler - Google Patents

Abstract

An apparatus for supplying fuel to a diesel engine provided with an EGR cooler may include a first supply line for directing fuel supplied from a fuel tank through a low-pressure pump into the EGR cooler, a second supply line, to introduce fuel passing through the EGR cooler into a common rail system through a high pressure pump, and a first bypass line to direct a portion of the fuel passing through the low pressure pump to a fuel mixing section upstream of the high pressure pump the second supply line is formed to mix the fuel with the fuel, which is cooled while passing through the EGR cooler.

Description

Background of the invention

Field of the invention

The present invention relates to an apparatus and a method for supplying fuel using an EGR (Exhaust Gas Recirculation) cooler, and more particularly, to an apparatus and method for supplying fuel using an EGR cooler in which a part of the fuel derived from a Fuel tank is supplied in the EGR cooler exchanges heat to control the temperature of fuel, which is supplied to a common rail system.

Description of the Related Art

Generally, the greater the temperature of fuel, the greater the efficiency of fuel, up to a predetermined value. In particular, with respect to fuel temperature dependent power measurements and test results of gasoline, in a gasoline direct injection engine, it can be understood that as the temperature of fuel is greater, the overall performance of an internal combustion engine, such as combustion stability and performance, is increased. Such performance improvement of an internal combustion engine is demonstrated by the fact that when the fuel temperature is increased while the fuel is being supplied from an injector, the atomization and injection width of the fuel are increased up to a predetermined temperature. When these results are applied to a direct injection diesel engine, it can be concluded that the fuel diffusion efficiency can be increased, and a mixture with air can be better produced up to a predetermined temperature, according to the increase of the atomization and the injection width of the fuel.

Meanwhile, is 1A a view illustrating a conventional fuel supply system of a diesel engine, and the conventional fuel supply system of an internal combustion engine has a structure in which the pressure of fuel from a fuel tank 11 of a vehicle through the pumps 12 . 14 is increased and the fuel is an injector 16 is supplied as in 1A shown. That is, the pressure of fuel is first through a low pressure pump 12 on a front of the fuel tank 11 increases, and the fuel is supplied to a fuel supply line, which with the high-pressure pump 14 connected is. At this time, fuel is flowing to a fuel temperature sensor 13 on a front of the high pressure pump 14 past. The fuel with high pressure, its pressure by the high-pressure pump 14 increased to 1800 bar (based on a U2 EU5 internal combustion engine) is provided by a common-rail system 15 via an injector 16 fed into a combustion chamber. The remaining fuel, which remains in the combustion chamber after feeding, is through a fuel return hose 17 in the fuel tank 11 recycled.

In the conventional supply system, as described above, the fuel density can only be compensated according to the temperature of fuel passing through the temperature sensor 13 is measured when feeding the fuel from the injector 16 , However, since it is not possible to maintain the temperature at which optimum combustion is possible, there is a limit to further improve the combustion efficiency.

Further is 1B a view illustrating a conventional EGR system, wherein the currently used EGR system uses cooling water as the refrigerant for cooling the EGR gas. That is, an EGR cooler 23 Cools EGR gas, which has a high temperature, by passing cooling water through a flow passage inside an EGR cooler 23 passes through and the EGR gas, which has a high temperature and from an exhaust manifold 21 is circulated to the EGR cooler and then to an intake manifold 26 is recycled, with the flow of EGR gas through an EGR valve 22 and a bypass valve for EGR gas 24 can be blocked or redirected according to the areas in which the EGR system is used. Further, the EGR gas temperature sensor is provided to measure the temperature of EGR gas and the measured value is utilized.

At this time, the cooling water used as refrigerant is the cooling water that is for an internal combustion engine 30 is used, and its temperature is maintained at about 80 ° C. However, the cooling effect can be improved as the temperature of the refrigerant further decreases.

Accordingly, the present applicant has realized the present invention based on the facts that the combustion efficiency of fuel can be improved by controlling the fuel temperature, while the cooling effect of an EGR system can be improved by supplying fuel supplied to a diesel engine. is used as refrigerant in the EGR system.

Meanwhile, a technology that raises the temperature of oil or cooling water has been proposed and used according to the related art by means of a device that recovers heat from an internal combustion engine.

According to the related art, thereby, the temperature increase of cooling water and oil is caused to increase the fuel ratio of a vehicle in a situation where fuel is consumed to a high degree, such as at startup, quick start, fast acceleration, or high speed driving Improve, and unnecessary heat exchange of cooling water can be prevented in a situation in which the heat exchange of cooling water is not necessary, thereby avoiding a decrease in performance of vehicle components that use cooling water. However, the combustion performance of fuel can not be expected to be improved.

The information disclosed in the background section of the invention is merely for a better understanding of the general background of the invention and should not be taken as an acknowledgment or any suggestion that this information constitutes prior art that is already known to one skilled in the art.

Short Summary

Various aspects of the present invention are directed to providing an apparatus and method for supplying fuel using an EGR cooler in which a portion of the fuel supplied from a fuel tank in the EGR cooler exchanges heat with the fuel Temperature of the fuel, which is supplied to a common rail system to control.

Further, various aspects of the present invention are directed to providing an apparatus and method for supplying fuel using an EGR cooler in which EGR gas cooling performance can also be improved because fuel having a lower temperature than cooling water, used as refrigerant in the EGR cooler.

According to various aspects of the present invention, an apparatus for supplying fuel to a diesel engine using an EGR cooler may include a first supply line for supplying fuel supplied from a fuel tank to the EGR cooler through a low-pressure pump Supply line for introducing fuel passing through the EGR cooler by a high-pressure pump in a common rail system, and a first bypass line to direct a portion of the fuel, which passes through the low-pressure pump to a fuel mixing section the high-pressure pump of the second supply line is formed to mix the fuel with the fuel, which is cooled while passing through the EGR cooler.

A fuel temperature sensor may be provided on the second supply line for measuring the fuel temperature between the fuel mixing section and the high pressure pump, and a second bypass line is provided on the first supply line for introducing a portion of the fuel passing through the low pressure pump into the first bypass Line, according to the fuel temperature value measured at the fuel temperature sensor.

A 3-way valve for controlling the amount of fuel supplied into the EGR cooler and the second bypass line may be provided at a junction of the first supply line and the second bypass line, and the 3-way valve may be controlled to adjust the amount of fuel that is introduced into the EGR cooler and the second bypass line, according to the fuel temperature value, which is measured at the fuel temperature sensor.

According to various aspects of the present invention, a method of supplying fuel to a diesel engine provided with an EGR cooler may include controlling a portion of the fuel to pass through an EGR cooler and then to a common rail system is to control the temperature of the fuel supplied from a fuel tank.

The method of supplying fuel to the diesel engine provided with an EGR cooler may further comprise first increasing the pressure of fuel supplied from the fuel tank to the low pressure pump, allowing a portion of the fuel, the pressure thereof has been increased a first time, passes through the EGR cooler, and the remainder of the fuel bypasses the EGR cooler to thereafter mix with each other, increasing the pressure of the mixed fuel for the second time at the high pressure pump, and supplying the common rail Systems with the fuel whose pressure was increased for the second time.

The method of supplying fuel to the diesel engine provided with an EGR cooler may further include measuring the temperature of the mixed fuel and controlling the amount of fuel passing through the EGR cooler and the amount of fuel bypassing the EGR cooler is based on the measured fuel temperature value.

The step of controlling the amount of fuel passing through the EGR cooler and the amount of fuel bypassing the EGR cooler; may include increasing the amount of fuel passing through the EGR cooler if the measured fuel temperature value is less than a predetermined optimum temperature value and increasing the amount of fuel bypassing the EGR cooler if the measured fuel temperature value is greater than the predetermined optimum temperature value is.

It should be understood that the term "vehicle," or "vehicle," or other similar terms as used herein, generally includes motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks , various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and include hybrid vehicles, electric vehicles, plug-in hybrid vehicles, hydrogen powered vehicles, and other alternative fuel vehicles (eg, fuel derived from other commodities) is recovered as petroleum). Herein, a hybrid vehicle means a vehicle having two or more drive sources, for example, vehicles that are both gasoline-powered and electric-powered.

The methods and apparatus of the present invention have other features and advantages as will become apparent from the accompanying drawings, which are incorporated herein by reference, and the following detailed description, which together serve to explain certain basic principles of the present invention.

Brief description of the drawings

1A FIG. 12 is a view schematically illustrating a fuel supply system of a related art diesel engine. FIG.

1B FIG. 13 is a view schematically illustrating an EGR system according to the related art. FIG.

2 FIG. 10 is a view illustrating an exemplary fuel supply apparatus using an EGR cooler according to the present invention. FIG.

3A and 3B FIG. 11 is views illustrating a flow of fuel and EGR gas when the exemplary fuel supply apparatus using an EGR cooler according to the present invention is used.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, particular dimensions, orientations, locations and shapes, will be determined in part by the particular application and the particular environment of use.

Detailed description

Reference will now be made in detail to various embodiments of the present invention (s), examples of which are illustrated in the accompanying drawings and described below. Although the invention (s) will be described in conjunction with the exemplary embodiments, it will be understood that the present description is not intended to limit the invention (s) to those exemplary embodiments. On the contrary, the invention (s) is intended / intended not only to protect the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments which are within the spirit and scope of the invention as defined in the appended claims ,

2 FIG. 14 is a view illustrating an apparatus for supplying fuel using an EGR cooler according to an embodiment of the present invention. FIG.

As in 2 1, the fuel supply apparatus using an EGR cooler according to various embodiments of the present invention is mostly composed of a structure for implementing an EGR system and a structure for a fuel supply system, wherein first, a first recycle gas line 30 for supplying EGR gas from an exhaust manifold 21 to an EGR cooler 23 is circulated, and a second circulating gas line 40 for recirculating the EGR gas in the EGR cooler 23 Heat exchanged, to an intake manifold 26 in the structure for implementing an EGR system. At this time is at the first recycle gas line 30 an EGR valve 22 provided and at the second circulating gas line 40 are a bypass valve for EGR gas 24 to block or divert the flow of EGR gas and a temperature sensor for EGR gas 25 provided for measuring the temperature of EGR gas.

Next, a first supply line is provided to the structure for a fuel supply system 110 for supplying fuel from a fuel tank 11 is fed to an EGR cooler 23 . a second supply line 120 for supplying the fuel to the EGR cooler 23 goes through, to a common-rail system 15 , and a first bypass line 210 for diverting a portion of the fuel from the fuel tank 11 to the first supply line 110 is supplied to the second supply line 120 , Further, a second bypass line 220 on a front of the EGR cooler 23 provided for diverting a portion of the fuel along the first supply line 110 flows, to the first bypass line 210 ,

Here is a low pressure pump 12 at the first supply line 110 provided for first pressurizing the fuel coming out of the fuel tank 11 is supplied, and further is an end of the first bypass line 210 , which is branched off from the first supply line 110 , connected to a back of the low pressure pump 12 , and the other end of the first bypass line 210 is connected to the second supply line 120 , At this time, a connection point of the other end designates the first bypass line 210 and the second supply line 120 a "fuel mixing section 400 ". Consequently, part of the fuel that is in the low-pressure pump 12 For the first time pressure was increased, increasing in temperature, by heat exchange with EGR gas, while the fuel through the EGR cooler 23 along the first supply line 110 flows, and is introduced into the fuel mixing section 400 and the remainder of the fuel which has been initially pressurized is introduced directly into the fuel mixing section 400 , along the first bypass line 210 to mix them together to maintain the proper temperature and pressure.

Further, a fuel mixing section 400 , a fuel temperature sensor 13 and a high pressure pump 14 provided, in turn, in the flow direction of the fuel along the second supply line 120 , Consequently, the temperature of the fuel that is at a suitable temperature and a suitable pressure in the fuel mixing section 400 is mixed while measuring the fuel temperature sensor 13 happens, and is then pressure-boosted for the second time, to a level common to the rail system 15 needed while passing through the high pressure pump 14 flows to the common-rail system 15 to be fed.

Meanwhile, a second bypass line 220 at the first supply line 110 provided for supplying a portion of the fuel to the low pressure pump 12 flows through, to the first bypass line 210 , according to the temperature value at the fuel temperature sensor 13 is measured. At this time is a 3-way valve 300 at a connection point of the first supply line 110 and the second bypass line 220 provided for controlling the amount of fuel flowing into the EGR cooler 23 and the second bypass line 220 is directed, and the 3-way valve 300 is with a magnet 310 for controlling the opening and closing of the 3-way valve 300 provided.

As a result, when the fuel temperature measured by the fuel temperature sensor 13 is less than the predetermined optimum temperature value, the fuel entering the first bypass line 210 , through the second bypass line 220 , is initiated, completely locked or the amount thereof is reduced, so that the amount of fuel flowing to the EGR cooler 23 temperature is increased, since the amount of fuel that the EGR cooler 23 flows through, is increased.

On the other hand, when the fuel temperature measured by the fuel temperature sensor 13 greater than the predetermined optimum temperature value, the amount of fuel flowing into the first bypass line 210 , through the second bypass line 220 , is initiated, increased, so that the amount of fuel flowing to the EGR cooler 23 is increased, since the amount of fuel flowing to the fuel mixing section 400 is diverted without the EGR cooler 23 to flow through, is increased.

Meanwhile, a method of supplying fuel using the fuel supply apparatus using an EGR cooler according to various embodiments of the present invention will be described with reference to the drawings.

3A and 3B FIG. 11 is views illustrating a flow of fuel and EGR gas when using an apparatus for supplying fuel using an EGR cooler according to various embodiments of the present invention. FIG.

As shown in the drawings, a basic idea of the method of supplying fuel using an EGR cooler according to various embodiments of the present invention is that a portion of the fuel is an EGR cooler 23 for effecting heat exchange with EGR gas and raising the temperature, and then a common rail system 15 is supplied to control the temperature of the fuel, which is a common rail system 15 , from a fuel tank 11 , is supplied.

Put differently, the low temperature of fuel is increased by the amount of fuel that is added to the EGR cooler 23 is added, to increase the temperature of fuel quickly to a suitable temperature, while driving in a section of the winter season (cold state) / medium load. For this purpose, as in 3A shown the fuel coming out of the fuel tank 11 is fed to the low pressure pump 12 Pressure increases for the first time, and a portion of the fuel that was initially pressurized increases in temperature as it travels along the first supply line 110 , through the EGR cooler 23 flows to a fuel mixing section 400 to be supplied, and the rest thereof is the fuel mixing section 400 supplied, while maintaining the initial increased pressure, adding fuel to the EGR cooler 23 is passed. At this time, the diversion of fuel from the first supply line 110 in the first bypass line 210 locked by the second bypass line 220 is closed.

As described above, the fuel that is raised in temperature by passing through the EGR cooler 23 flows, and the fuel, which was first increased pressure and the EGR cooler 23 is bypassed, in the fuel mixing section 400 mixed to obtain the appropriate temperature and pressure.

The temperature of fuel mixed at the appropriate temperature and pressure is measured as it senses the fuel temperature sensor 13 happens, and the fuel is then pressure-boosted for a second time, to a level common to the common-rail system 15 needed while passing through the high pressure pump 14 flows to the common-rail system 15 to be fed.

Meanwhile, if a fuel temperature value, measured on the fuel temperature sensor 13 is greater than the predetermined optimum temperature, or when a vehicle is driven in a section of a warm state / medium load, as in 3B shown, part of the fuel to the second bypass line 220 diverted by controlling the 3-way valve 300 , whereby an optimum temperature is maintained, as the temperature of fuel in the fuel mixing section 400 is mixed, gets smaller.

Further, when a fuel temperature value measured at the fuel temperature sensor 13 is smaller than the predetermined optimum temperature value, when supplying fuel in the above state, the amount of fuel flowing to the second bypass line becomes 220 is diverted, reduced or completely interrupted by re-controlling the 3-way valve 300 , causing the temperature of fuel in the fuel mixing section 400 is mixed, gets bigger.

As described above, the amount of fuel passing through the EGR cooler 23 flows or the the EGR cooler 23 bypasses, suitably controlled, according to the temperature value at the fuel temperature sensor 13 is measured, or according to the driving state, whereby an optimum fuel temperature is maintained to improve the combustion efficiency of fuel.

According to various embodiments of the present invention, a part of the fuel supplied from a fuel tank exchanges heat in an EGR cooler to increase the temperature of the fuel supplied to a common rail system, and is supplied with the Remainder of the fuel bypassing the EGR cooler is mixed to thereby control the temperature to improve combustion efficiency.

Further, the fuel having a lower temperature than the cooling water is used as the refrigerant of an EGR cooler to exchange heat with EGR gas to thereby improve the EGR gas cooling performance.

For convenience of explanation and precise definition, in the appended claims, the terms "upper," "lower," "inner," and "outer" are used to describe features of the embodiments with respect to the positions of those features, as described in U.S. Pat the figures are shown.

The foregoing descriptions of the specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and it is apparent that many modifications and variations are possible in light of the above teachings. The embodiments have been chosen and described to illustrate certain principles of the invention and their practical application to thereby enable those skilled in the art to make and use various embodiments of the present invention as well as various alternatives and changes thereto. It is intended that the scope of the invention be defined by the appended claims and their equivalents.

Claims (7)

An apparatus for supplying fuel to a diesel engine provided with an EGR cooler, comprising: a first supply line for supplying fuel supplied from a fuel tank to the EGR cooler through a low-pressure pump; a second supply line for introducing fuel passing through the EGR cooler into a common rail system through a high pressure pump; and a first bypass passage for directing a portion of the fuel passing through the low-pressure pump to a fuel mixing section formed in front of the high-pressure pump of the second supply line to mix the fuel with the fuel being cooled while discharging the EGR Cooler passes through. The apparatus for supplying fuel to a diesel engine provided with an EGR cooler according to claim 1, wherein a fuel temperature sensor is provided at the second supply line for measuring the fuel temperature between the fuel mixing section and the high-pressure pump, and wherein a second bypass Line is provided at the first supply line, for introducing a portion of the fuel, which passes through the low pressure pump, in the first bypass line, according to the fuel temperature value, which is measured at the fuel temperature sensor. The apparatus for supplying fuel to a diesel engine provided with an EGR cooler according to claim 2, wherein a 3-way valve for controlling the amount of fuel supplied into the EGR cooler and the second bypass pipe, is provided at a junction of the first supply line and the second bypass line, and wherein the 3-way valve is controlled to control the amount of fuel introduced into the EGR cooler and the second bypass line according to the fuel temperature value is measured at the fuel temperature sensor to adjust. A method of supplying fuel to a diesel engine provided with an EGR cooler, comprising controlling a portion of the fuel to pass through an EGR cooler and then to a common rail system to determine the temperature of the fuel which is supplied from a fuel tank to control. The method of supplying fuel to a diesel engine provided with an EGR cooler according to claim 4, further comprising: First increasing the pressure of fuel supplied from the fuel tank to the low pressure pump; Allowing a portion of the fuel whose pressure has been increased a first time to pass through the EGR cooler and the remainder of the fuel bypassing the EGR cooler to thereafter mix with each other; Increasing the pressure of the mixed fuel for the second time on the high pressure pump; and Supplying the common rail system with the fuel whose pressure has been increased for the second time. The method of supplying fuel to a diesel engine provided with an EGR cooler according to claim 5, further comprising measuring the temperature of the mixed fuel and controlling the amount of fuel passing through the EGR cooler and the amount of fuel flowing to the EGR Cooler is passed, based on the measured fuel temperature value. The method of supplying fuel to a diesel engine provided with an EGR cooler according to claim 6, wherein the step of controlling the amount of fuel passing through the EGR cooler and the amount of fuel bypassing the EGR cooler comprises increasing the amount of fuel passing through the EGR cooler if the measured fuel temperature value is less than a predetermined optimum temperature value and increasing the amount of fuel bypassing the EGR cooler if the measured fuel temperature value is greater than the predetermined optimum temperature value is.

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